content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.observable.internal.operators;
  
  import java.util.concurrent.atomic.*;
  
  import io.reactivex.common.Disposable;
  import io.reactivex.common.exceptions.Exceptions;
  import io.reactivex.common.functions.Function;
  import io.reactivex.common.internal.disposables.DisposableHelper;
  import io.reactivex.common.internal.functions.ObjectHelper;
  import io.reactivex.common.internal.utils.AtomicThrowable;
  import io.reactivex.observable.*;
  import io.reactivex.observable.internal.disposables.EmptyDisposable;
  import io.reactivex.observable.internal.utils.HalfSerializer;
  import io.reactivex.observable.subjects.*;
  
  /**
   * Repeatedly subscribe to a source if a handler ObservableSource signals an item.
   *
   * @param <T> the value type
   */
  public final class ObservableRetryWhen<T> extends AbstractObservableWithUpstream<T, T> {
  
      final Function<? super Observable<Throwable>, ? extends ObservableSource<?>> handler;
  
      public ObservableRetryWhen(ObservableSource<T> source, Function<? super Observable<Throwable>, ? extends ObservableSource<?>> handler) {
          super(source);
          this.handler = handler;
      }
  
      @Override
      protected void subscribeActual(Observer<? super T> observer) {
          Subject<Throwable> signaller = PublishSubject.<Throwable>create().toSerialized();
  
          ObservableSource<?> other;
  
          try {
              other = ObjectHelper.requireNonNull(handler.apply(signaller), "The handler returned a null ObservableSource");
          } catch (Throwable ex) {
              Exceptions.throwIfFatal(ex);
              EmptyDisposable.error(ex, observer);
              return;
          }
  
          RepeatWhenObserver<T> parent = new RepeatWhenObserver<T>(observer, signaller, source);
          observer.onSubscribe(parent);
  
          other.subscribe(parent.inner);
  
          parent.subscribeNext();
      }
  
      static final class RepeatWhenObserver<T> extends AtomicInteger implements Observer<T>, Disposable {
  
          private static final long serialVersionUID = 802743776666017014L;
  
          final Observer<? super T> actual;
  
          final AtomicInteger wip;
  
          final AtomicThrowable error;
  
          final Subject<Throwable> signaller;
  
          final InnerRepeatObserver inner;
  
          final AtomicReference<Disposable> d;
  
          final ObservableSource<T> source;
  
          volatile boolean active;
  
          RepeatWhenObserver(Observer<? super T> actual, Subject<Throwable> signaller, ObservableSource<T> source) {
              this.actual = actual;
              this.signaller = signaller;
              this.source = source;
              this.wip = new AtomicInteger();
              this.error = new AtomicThrowable();
              this.inner = new InnerRepeatObserver();
              this.d = new AtomicReference<Disposable>();
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              DisposableHelper.replace(this.d, d);
          }
  
          @Override
          public void onNext(T t) {
              HalfSerializer.onNext(actual, t, this, error);
          }
  
          @Override
          public void onError(Throwable e) {
              active = false;
              signaller.onNext(e);
          }
  
          @Override
          public void onComplete() {
              DisposableHelper.dispose(inner);
              HalfSerializer.onComplete(actual, this, error);
          }
  
          @Override
          public boolean isDisposed() {
              return DisposableHelper.isDisposed(d.get());
          }
  
          @Override
          public void dispose() {
              DisposableHelper.dispose(d);
              DisposableHelper.dispose(inner);
          }
  
          void innerNext() {
              subscribeNext();
          }
  
          void innerError(Throwable ex) {
              DisposableHelper.dispose(d);
              HalfSerializer.onError(actual, ex, this, error);
          }
  
          void innerComplete() {
              DisposableHelper.dispose(d);
              HalfSerializer.onComplete(actual, this, error);
          }
  
          void subscribeNext() {
              if (wip.getAndIncrement() == 0) {
  
                  do {
                      if (isDisposed()) {
                          return;
                      }
  
                      if (!active) {
                          active = true;
                          source.subscribe(this);
                      }
                  } while (wip.decrementAndGet() != 0);
              }
          }
  
          final class InnerRepeatObserver extends AtomicReference<Disposable> implements Observer<Object> {
  
              private static final long serialVersionUID = 3254781284376480842L;
  
              @Override
              public void onSubscribe(Disposable d) {
                  DisposableHelper.setOnce(this, d);
              }
  
              @Override
              public void onNext(Object t) {
                  innerNext();
              }
  
              @Override
              public void onError(Throwable e) {
                  innerError(e);
              }
  
              @Override
              public void onComplete() {
                  innerComplete();
              }
          }
      }
  }
  